A miniature dynamic penetration test apparatus

Abstract

This utility model provides a miniature dynamic penetration test device, belonging to the field of engineering survey technology. It includes a hammer, guide rod, force transmission body, probe rod, and cone head, arranged from top to bottom. The hammer includes at least two sub-hammers, each with an axially penetrating guide hole at its center. The sub-hammers are fitted onto the guide rod through the guide hole and slide freely along the axial direction of the guide rod. Each sub-hammer has at least two axially penetrating positioning holes evenly distributed around the guide hole. Fasteners are used to fix at least two sub-hammers within the positioning holes. The lower end of the guide rod is connected to the upper end of the force transmission body, the lower end of the force transmission body is connected to the upper end of the probe rod, and the lower end of the probe rod is connected to the upper end of the cone head. The hammer of this utility model can be disassembled and fixed using fasteners, and the overall structure is easy to assemble and disassemble. The device is lightweight, portable, easy to operate, requires less physical exertion from operators, and has low operating costs.

Description

Technical Field

[0001] This utility model relates to the field of engineering survey technology, specifically to a micro dynamic penetration test device. Background Technology

[0002] Currently, dynamic penetration testing (VPPT) is a common exploration method that plays an important role in engineering surveys. Conventional VPTs are divided into three types: light VPT, heavy VPT, and super-heavy VPT. The main difference lies in the weight of the test hammer and the diameter of the probe. Heavy and super-heavy VPTs require mechanical equipment (generally drilling rigs), while light VPTs can be conducted using either mechanical equipment or manually. Even though the overall weight of light VPT equipment is lighter (the hammer weighs 10 kg, and the probe is a 25 mm diameter, 1 m long iron cylinder), a typical VPT still requires a hammer, a probe several meters to tens of meters long, and some auxiliary tools. While this is not a problem in plains areas where it can be carried by means of transport, mountainous areas often lack roads accessible to vehicles. In particular, dynamic penetration tests in mountainous areas can only be conducted manually, placing a heavy physical burden on the workers. For linear projects in mountainous areas (such as high-voltage transmission towers, highways, and railways), the distance between each dynamic penetration test point can be tens to hundreds of meters or even longer. Multiple dynamic penetration tests need to be completed every day, requiring traversing mountains and valleys. Once at the test point, the dynamic penetration test equipment needs to be operated manually. Carrying the dynamic penetration test equipment and working on-site are extremely physically demanding for the workers, seriously affecting the quality and progress of the exploration work. Furthermore, working under fatigue poses significant safety hazards.

[0003] Existing technology (CN213571872U) provides an ultralight cone penetrometer, including a powered penetrometer hammer, a cone penetrometer probe, and a penetrometer rod connecting the hammer and probe. The powered penetrometer hammer includes a center hammer, a guide rod passing through the center hammer, and a hammer pad connecting the guide rod and the penetrometer rod. The center hammer has symmetrical handles at both ends for lifting and operation. The cone penetrometer probe includes a cylindrical section connecting the penetrometer rod and a conical section for testing. Although this invention reduces the overall weight of the device, the center hammer still weighs 2.5 kg, is not detachable, and is relatively large, which would place a significant physical burden on operators during transportation. Utility Model Content

[0004] The technical problem to be solved by this utility model is that existing dynamic penetrometers are large in size, difficult to transport, and impose a great physical burden on operators. In order to solve the above problems, a miniature dynamic penetrometer test device is provided.

[0005] This utility model is achieved in the following manner:

[0006] A miniature dynamic penetrometer includes a hammer, a guide rod, a force transmission body, a probe, and a cone. The hammer, guide rod, force transmission body, probe, and cone are arranged from top to bottom. The hammer includes at least two sub-hammers. Each sub-hammer has an axially penetrating guide hole at its center. The sub-hammer is sleeved on the guide rod through the guide hole and slides freely along the axial direction of the guide rod. Each sub-hammer has at least two axially penetrating positioning holes evenly distributed around the guide hole. At least two sub-hammers are fixed in the positioning holes by bolts or screws with nuts.

[0007] The lower end of the guide rod is connected to the upper end of the force transmission body, the lower end of the force transmission body is connected to the upper end of the probe rod, and the lower end of the probe rod is connected to the upper end of the cone.

[0008] Preferably, the hammer weighs 1.0 kg and has a diameter of 50-70 mm.

[0009] Preferably, the drop distance of the hammer is 80cm.

[0010] Preferably, the guide rod and the force transmission body, the force transmission body and the probe rod, and the probe rod and the cone head are all detachably connected.

[0011] Preferably, the detachable connection is a threaded connection.

[0012] Preferably, the guide rod has a diameter of 10mm and a length of 1.0m.

[0013] Preferably, the force-transmitting body is in the shape of an inverted triangular cone, with an upper diameter of 25-35 mm and a lower diameter of 10 mm.

[0014] Preferably, there are at least two probes, which are detachably connected; the probes have a diameter of 10mm and a length of 1.0m.

[0015] Preferably, the cone head includes an upper frustum section, a middle cylindrical section, and a lower conical section. The upper diameter of the upper frustum section is 10 mm, the outer diameter of the middle cylindrical section is 15 mm, and the cone angle of the lower conical section is 60°.

[0016] Compared with existing technologies, the mandrel of this invention can be disassembled and fixed through connecting rods and fasteners, and the overall structure is easy to disassemble and assemble. The equipment is lightweight, easy to carry, easy to operate, requires less physical exertion from operators, and has low operating costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2This is a top view of the mandrel hammer of this utility model.

[0019] Among them, 1 is the through hammer; 2 is the guide rod; 3 is the force transmission body; 4 is the probe rod; 5 is the cone head; 11 is the sub-hammer; 12 is the handle; 13 is the screw; 14 is the nut; 111 is the guide hole; and 112 is the positioning hole. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, unless otherwise specified, the specific experimental methods involved in the following embodiments are conventional methods or implemented according to the conditions recommended in the manufacturer's instructions.

[0021] See Figure 1 , 2 A miniature dynamic penetrometer test device includes a penetrometer 1, a guide rod 2, a force transmission body 3, a probe rod 4, and a cone head 5. The penetrometer 1, guide rod 2, force transmission body 3, probe rod 4, and cone head 5 are arranged from top to bottom. The penetrometer 1 includes at least two sub-hammers 11, but can have three or four to reduce the weight of a single sub-hammer, allowing different operators to carry them and reducing their burden. Each sub-hammer 11 is cylindrical, with an axially penetrating guide hole 111 at its center. The diameter of the guide hole is slightly larger than the diameter of the guide rod. The sub-hammers 11 are sequentially fitted onto the guide rod 2 through the guide hole 111 and slide freely along the axial direction of the guide rod 2. Each sub-hammer 11 has at least two axially penetrating positioning holes 112, evenly distributed around the guide hole 111. At least two sub-hammers are fixed within the positioning holes 112 by bolts or screws with nuts. Figure 1 As shown, a screw 13 passes through the positioning hole 112, and nuts 14 are provided at both ends of the screw 13. The sub-hammers 11 are fixedly connected by the long screw 13 and the nuts 14. Preferably, the penetrating hammer includes three sub-hammers, which are sequentially sleeved on the guide rod 2. The bottom sub-hammer has two symmetrical handles 12 on its outer side for lifting and operation. The sub-hammers 11 have four axially penetrating positioning holes 112. In use, four long screws are respectively inserted into the positioning holes, and two nuts are provided at one end of each screw. The four long screws and 16 nuts are used to fix the three sub-hammers to form the penetrating hammer. After the operation is completed, the penetrating hammer can be disassembled, and each sub-hammer can be carried by different operators, reducing the transportation burden. The penetrating hammer is easy to disassemble, assemble, and carry, which can reduce the physical exertion of operators. In addition, operators can also choose different numbers of sub-hammers to conduct dynamic penetration tests.

[0022] The lower end of the guide rod 2 is connected to the upper end of the force transmission body 3, the lower end of the force transmission body 3 is connected to the upper end of the probe rod 4, and the lower end of the probe rod 4 is connected to the upper end of the cone head 5.

[0023] Furthermore, the weight of the sub-hammer 11 is 1.0 kg, the diameter is 50~70 mm, and the drop distance of the through hammer 1 is 80 cm; preferably, the diameter of the sub-hammer 11 is 60 mm, and the drop distance of the through hammer 1 is 80 cm; the three sub-hammers are fixed by four screws and 16 nuts, forming a through hammer 1 with an overall weight of 3 kg, wherein the weight of the screws and nuts is negligible.

[0024] Furthermore, the guide rod 2 and the force transmission body 3, the force transmission body 3 and the probe rod 4, and the probe rod 4 and the cone head 5 are all detachably connected; the detachable connections are threaded connections. This facilitates the assembly, disassembly, and carrying of the miniature powered penetrometer.

[0025] In detail, the guide rod 2 is generally slender cylindrical with a male thread at the lower end; the force transmission body 3 is in the shape of an inverted triangular cone with a female thread at the center of the upper end and a male thread at the lower end; the probe rod 4 is slender cylindrical with a female thread at the upper end and a male thread at the lower end; the cone head 5 includes an upper frustum section, a middle cylindrical section and a lower conical section, with a female thread at the center of the upper end.

[0026] Furthermore, the guide rod 2 has a diameter of 10mm and a length of 1.0m.

[0027] The force transmission body 3 is in the shape of an inverted triangular cone, with an upper diameter of 25-35mm and a lower diameter of 10mm; preferably, the upper diameter of the force transmission body is 30mm and the lower diameter is 10mm.

[0028] There are at least two probe rods 4, which are detachably connected. The probe rods 4 have a diameter of 10mm and a length of 1.0m.

[0029] The cone 5 includes an upper frustum section, a middle cylindrical section, and a lower conical section. The upper diameter of the upper frustum section is 10 mm, the outer diameter of the middle cylindrical section is 15 mm, and the cone angle of the lower conical section is 60°.

[0030] The process of using this utility model is as follows: Upon arriving at the test point, four long screws are used to pass through the four positioning holes 112 of the sub-hammers 11 respectively. Three sub-hammers 11 are then sequentially mounted on the long screws, with the sub-hammer with the handle located at the bottom. Hexagonal nuts are installed at both ends of the long screws for limiting and tightening, thus fixing the three sub-hammers to form the penetrating hammer 1. The lower end of a probe rod 4 is threaded to a cone head 5, and the upper end is threaded to the lower end of the force transmission body 3. After the guide rod 2 is inserted into the penetrating hammer 1, its lower end is threaded to the upper end of the force transmission body 3, and the dynamic penetration test begins. Mark the probe rod every 10cm. Manually lift the mandrel 80cm up the guide rod and let it fall freely. After hitting the force transmission body, the force transmission body will drive the probe rod and cone head to move downwards and into the soil. Repeat this process and record the number of hammer blows for every 10cm the probe rod moves downwards. After the probe rod is completely in the soil, remove the force transmission body at the top of the probe rod, add another probe rod, and continue the above test steps until the cone head reaches the designed test depth or can no longer be driven in. This completes the dynamic penetration test of one test point.

[0031] After the test was completed, the probe and probe were manually pulled out using the existing pull-out tools.

[0032] It should be noted that, as a new type of exploration equipment, the experimental data obtained by this utility model needs to be calibrated beforehand.

[0033] Calibration method: Using conventional static cone penetration test, light dynamic cone penetration test, geotechnical test, and the micro dynamic cone penetration test of this utility model, comparative tests were conducted on different states of cohesive soil, silt, and sand (such as stiff plastic, plastic, soft plastic, and fluid plastic of cohesive soil; loose, slightly dense, medium dense, and dense of silt and sand). Through comparative analysis of test data, the correspondence between the number of blows (N) per 10cm penetration of the soil layer in the micro dynamic cone penetration test and the soil state and the bearing capacity range of the foundation was established, and the equipment calibration was completed.

[0034] Data processing: Based on the micro dynamic penetration test data from various test points at the same site, soil layers are divided according to geological conditions; then, statistical analysis is performed on the data from all test points for each soil layer to calculate the average, range, and coefficient of variation of the number of blows (N) for each soil layer; based on the average N and calibration data, the state or bearing capacity of each soil layer is determined; combined with parameters such as the range of N and coefficient of variation, the state of the soil layer or the bearing capacity of the foundation is reasonably corrected to ensure the reliability of the evaluation results.

[0035] This invention features lightweight, portable, and easy-to-operate equipment that minimizes physical exertion on workers and reduces operating costs. It can be used for both surveying and foundation testing; its benefits are even more pronounced in mountainous areas without roads, significantly reducing the physical burden on workers and saving surveying costs. For linear projects in mountainous regions (such as high-voltage power transmission towers, highways, and railways), where the distance between each dynamic penetration test point ranges from tens to hundreds of meters or even longer, requiring workers to carry surveying equipment across mountains, the lightweight advantage of this invention is further highlighted. It significantly improves the quality and progress of surveying work and greatly reduces safety hazards associated with workers operating under fatigue.

[0036] The above description is only a preferred embodiment of the present utility model. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present utility model, and these should also be considered within the protection scope of the present utility model.

Claims

1. A miniature dynamic penetrometer, comprising a hammer (1), a guide rod (2), a force transmission body (3), a probe (4), and a cone (5), wherein the hammer (1), guide rod (2), force transmission body (3), probe (4), and cone (5) are arranged from top to bottom, characterized in that, The hammer (1) includes at least two sub-hammers (11). The sub-hammers (11) have an axially penetrating guide hole (111) at their center. The sub-hammers (11) are sleeved on the guide rod (2) through the guide hole (111) and slide freely along the axial direction of the guide rod (2). The sub-hammers (11) have at least two axially penetrating positioning holes (112). The positioning holes (112) are evenly distributed around the guide hole (111). The positioning holes (112) are fixed in the positioning holes (112) by bolts or screws in conjunction with nuts. The lower end of the guide rod (2) is connected to the upper end of the force transmission body (3), the lower end of the force transmission body (3) is connected to the upper end of the probe rod (4), and the lower end of the probe rod (4) is connected to the upper end of the cone (5).

2. A micro-cone penetration test apparatus according to claim 1, wherein The weight of the hammer (11) is 1.0 kg and the diameter is 50~70 mm.

3. A micro-cone penetration test apparatus according to claim 2, wherein The drop distance of the hammer (1) is 80cm.

4. The miniature dynamic penetration test apparatus according to claim 1, wherein The guide rod (2) and the force transmission body (3), the force transmission body (3) and the probe rod (4), and the probe rod (4) and the cone (5) are all detachable connections.

5. A micro-cone penetration test apparatus according to claim 4, wherein The detachable connection is a threaded connection.

6. A micro-cone penetration test apparatus according to claim 5, wherein The guide rod (2) has a diameter of 10 mm and a length of 1.0 m.

7. A micro-cone penetration test apparatus according to claim 6, wherein The force transmission body (3) is in the shape of an inverted triangular cone, with an upper diameter of 25~35mm and a lower diameter of 10mm.

8. A miniature dynamic penetration test device according to claim 7, characterized in that, There are at least two probes (4), and the probes are detachably connected; the probes (4) have a diameter of 10mm and a length of 1.0m.

9. A miniature dynamic penetration test device according to claim 8, characterized in that, The cone (5) includes an upper frustum section, a middle cylindrical section and a lower conical section. The upper diameter of the upper frustum section is 10 mm, the outer diameter of the middle cylindrical section is 15 mm, and the cone angle of the lower conical section is 60°.

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